fix: set X-Glean-Include-Experimental header (not X-Glean-Experimental)

The XGlean before_request hook read the correct include_experimental
option and X_GLEAN_INCLUDE_EXPERIMENTAL env var but emitted the wrong
header name. The backend expects X-Glean-Include-Experimental. Correct
the header name in the hook and tests.

Author: travis-hoover-glean

src/glean/api_client/_hooks/x_glean.py

@@ -27,7 +27,7 @@ class XGlean(BeforeRequestHook):
 
     This hook adds the following headers when configured:
     - X-Glean-Exclude-Deprecated-After: Excludes API endpoints deprecated after this date
-    - X-Glean-Experimental: Enables experimental API features
+    - X-Glean-Include-Experimental: Enables experimental API features
 
     Configuration can be done via environment variables or SDK constructor options.
     Environment variables take precedence over SDK constructor options.
@@ -65,6 +65,6 @@ def before_request(
             request.headers["X-Glean-Exclude-Deprecated-After"] = deprecated_value
 
         if experimental_value:
-            request.headers["X-Glean-Experimental"] = experimental_value
+            request.headers["X-Glean-Include-Experimental"] = experimental_value
 
         return request

tests/test_x_glean_hook.py

@@ -72,7 +72,7 @@ def test_no_headers_when_neither_options_nor_env_vars_set(self):
         result = hook.before_request(context, request)
 
         assert "X-Glean-Exclude-Deprecated-After" not in result.headers
-        assert "X-Glean-Experimental" not in result.headers
+        assert "X-Glean-Include-Experimental" not in result.headers
 
     def test_sets_deprecated_header_from_sdk_option(self):
         """Should set X-Glean-Exclude-Deprecated-After header from SDK option."""
@@ -85,24 +85,24 @@ def test_sets_deprecated_header_from_sdk_option(self):
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2026-10-15"
 
     def test_sets_experimental_header_when_include_experimental_is_true(self):
-        """Should set X-Glean-Experimental header when includeExperimental is True."""
+        """Should set X-Glean-Include-Experimental header when includeExperimental is True."""
         hook = XGlean()
         request = create_mock_request()
         context = create_mock_context(include_experimental=True)
 
         result = hook.before_request(context, request)
 
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_no_experimental_header_when_include_experimental_is_false(self):
-        """Should not set X-Glean-Experimental header when includeExperimental is False."""
+        """Should not set X-Glean-Include-Experimental header when includeExperimental is False."""
         hook = XGlean()
         request = create_mock_request()
         context = create_mock_context(include_experimental=False)
 
         result = hook.before_request(context, request)
 
-        assert "X-Glean-Experimental" not in result.headers
+        assert "X-Glean-Include-Experimental" not in result.headers
 
     def test_sets_both_headers_when_both_options_provided(self):
         """Should set both headers when both options are provided."""
@@ -116,7 +116,7 @@ def test_sets_both_headers_when_both_options_provided(self):
         result = hook.before_request(context, request)
 
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2026-10-15"
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_sets_deprecated_header_from_env_var(self):
         """Should set X-Glean-Exclude-Deprecated-After header from environment variable."""
@@ -131,7 +131,7 @@ def test_sets_deprecated_header_from_env_var(self):
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2027-01-01"
 
     def test_sets_experimental_header_from_env_var(self):
-        """Should set X-Glean-Experimental header from environment variable."""
+        """Should set X-Glean-Include-Experimental header from environment variable."""
         os.environ["X_GLEAN_INCLUDE_EXPERIMENTAL"] = "true"
 
         hook = XGlean()
@@ -140,7 +140,7 @@ def test_sets_experimental_header_from_env_var(self):
 
         result = hook.before_request(context, request)
 
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_sets_both_headers_from_env_vars(self):
         """Should set both headers from environment variables."""
@@ -154,7 +154,7 @@ def test_sets_both_headers_from_env_vars(self):
         result = hook.before_request(context, request)
 
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2027-06-15"
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_env_var_takes_precedence_for_deprecated(self):
         """Environment variable should take precedence over SDK option for deprecated."""
@@ -178,7 +178,7 @@ def test_env_var_takes_precedence_for_experimental(self):
 
         result = hook.before_request(context, request)
 
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_env_vars_take_precedence_for_both_headers(self):
         """Environment variables should take precedence for both headers when all are set."""
@@ -195,7 +195,7 @@ def test_env_vars_take_precedence_for_both_headers(self):
         result = hook.before_request(context, request)
 
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2028-01-01"
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_preserves_existing_headers(self):
         """Should preserve existing headers when adding X-Glean headers."""
@@ -215,7 +215,7 @@ def test_preserves_existing_headers(self):
         assert result.headers.get("Authorization") == "Bearer token"
         assert result.headers.get("Content-Type") == "application/json"
         assert result.headers.get("X-Glean-Exclude-Deprecated-After") == "2026-10-15"
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
 
     def test_returns_httpx_request_instance(self):
         """Should return an httpx.Request instance."""
@@ -257,7 +257,7 @@ def test_handles_multipart_streaming_request(self):
 
         result = hook.before_request(context, request)
 
-        assert result.headers.get("X-Glean-Experimental") == "true"
+        assert result.headers.get("X-Glean-Include-Experimental") == "true"
         assert result.method == "POST"